The present invention relates to a lining for the interior of a furnace, for example a refractory lining to be employed in a furnace to melt glass. The present invention also relates to lining brick configurations employable for forming such furnace lining.
More particularly, the present invention relates to such lining brick or furnace lining having therein at least one depression defining internal wall surfaces that reflect radiant heat impinging thereon from the interior of the furnace through an opening in the inner surface of the lining brick or lining leading to the depression.
A lining brick and furnace lining of this type are disclosed in German DE 28 14 250 wherein depressions are designed in a manner such that heat reflecting surfaces thereof are as large as possible. To achieve such end, the depressions are configured in the shapes of pyramidal or conical frustrums. As such, the opening from the furnace interior into each depression forms the largest part of each depression. In other words, the cross-sectional area of the opening of each depression is larger than all internal cross-sectional areas of such depression. Therefore, the maximum amount of radiant heat striking the furnace lining is reflected onto the glass to be melted. This is said to be done in order to increase the efficiency of the glass-melting furnace. However, in such arrangement the heat radiation impinging on the surfaces of the depressions is reflected predominantly directly back into the interior of the furnace chamber, similar to the manner of reflection in a furnace having a smooth dome, i.e. without depressions. With such reflection of flame and gas heat radiation, reabsorption occurs. This reabsorbed radiation energy does not reach the material, for example glass, to be heated.
It has been found that increasing the heat reflection capabilities of the furnace lining does not lead to further improvements, since a portion of the reflected thermal radiation is reabsorbed by the source of such radiation, i.e. the flame employed to emit the heat, due to identical wave lengths.